KR101270537B1 - Air conditioner and method of controlling the same - Google Patents

Abstract

An air conditioner and a control method thereof are disclosed. An object of the present invention is to be able to calculate the current total amount of refrigerant charged in the refrigerant cycle through the rating of the compressor and the temperature and pressure characteristics of the input and output refrigerant of the compressor. An air conditioner according to the present invention for this purpose includes a compressor; An outdoor heat exchanger; An indoor heat exchanger; A refrigerant passage for connecting the compressor, the outdoor heat exchanger, and the indoor heat exchanger in order to circulate the refrigerant; Perform cooling operation so that the refrigerant discharged from the compressor is concentrated to the outdoor heat exchanger, and then switch to heating operation so that all refrigerant concentrated at the outdoor heat exchanger side is moved to the indoor heat exchanger through the compressor, and the refrigerant state information is transferred to the compressor. And a control unit for calculating the amount of refrigerant per unit time passing through the compressor by integrating the performance data, and integrating the amount of refrigerant per unit time to determine the total amount of refrigerant charged in the air conditioner.

Description

Air conditioner and control method {AIR CONDITIONER AND METHOD OF CONTROLLING THE SAME}

1 is a view showing the configuration of an air conditioner according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a control system of the air conditioner shown in FIG. 1. FIG.

3 is a graph showing the relationship of mass to evaporation temperature of a refrigerant.

4 is a flowchart illustrating a control method of an air conditioner according to an embodiment of the present invention.

Description of the Related Art [0002]

116: indoor heat exchanger

118: Compressor

122: outdoor heat exchanger

130: four way valve

154: receiver

156: gas-liquid separator

172, 176: first and second valve

174, 178: first and second expansion device

182 and 184: first refrigerant state detection sensor (first pressure sensor and first temperature sensor)

186, 188: second refrigerant state detection sensor (second pressure sensor and second temperature sensor)

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner and a control method thereof, and more particularly, to an air conditioner for detecting the total amount of refrigerant charged in a refrigerant cycle of an air conditioner and a control method thereof.

In the air conditioner, the refrigerant compressed to high temperature and high pressure in the compressor is cooled to low temperature through heat exchange with outdoor air in the outdoor heat exchanger. It has a structure for cooling the air.

On the contrary, the heating (heating) of the indoor air becomes a low temperature through the heat exchange with the indoor air in the indoor heat exchanger, the refrigerant compressed to high temperature and high pressure in the compressor, and the indoor air is heated in this process.

A pipe for refrigerant circulation, that is, a refrigerant pipe is installed between the outdoor unit and the indoor unit of the air conditioner. In particular, since a multi-system having a plurality of indoor units has a very long length of the refrigerant tube, a refrigerant tube having a suitable length is connected and installed by welding or the like. However, if the welding of the refrigerant pipe is not made properly or if sufficient management is not made, the welded part may be broken, and the refrigerant may leak into this part. In addition, the fatigue phenomena due to long periods of operation of the air conditioner may loosen the refrigerant pipe connection part, and the refrigerant may leak to this part. If the amount of refrigerant is insufficient due to the leakage of refrigerant, the air conditioner cannot fully exhibit its original cooling and heating ability. Therefore, when it is determined that the refrigerant is insufficient, the air conditioner must be compensated for the insufficient amount of refrigerant to provide sufficient cooling and heating ability. There is a need for an apparatus and method capable of detecting the amount of refrigerant.

An object of the present invention is to be able to calculate the current total amount of refrigerant charged in the refrigerant cycle through the rating of the compressor and the temperature and pressure characteristics of the input and output refrigerant of the compressor.

An air conditioner according to the present invention for this purpose includes a compressor; An outdoor heat exchanger; An indoor heat exchanger; A refrigerant passage for connecting the compressor, the outdoor heat exchanger, and the indoor heat exchanger in order to circulate the refrigerant; Perform cooling operation so that the refrigerant discharged from the compressor is concentrated to the outdoor heat exchanger, and then switch to heating operation so that all refrigerant concentrated at the outdoor heat exchanger side is moved to the indoor heat exchanger through the compressor, and the refrigerant state information is transferred to the compressor. And a control unit for calculating the amount of refrigerant per unit time passing through the compressor by integrating the performance data, and integrating the amount of refrigerant per unit time to determine the total amount of refrigerant charged in the air conditioner.

In addition, the above-described air conditioner further includes a four-way valve for changing the circulation direction of the refrigerant discharged from the compressor according to the cooling mode and the heating mode so that the refrigerant flows to either the outdoor heat exchanger or the indoor heat exchanger.

In addition, the above-described air conditioner includes: a first refrigerant state detection sensor provided in a suction side refrigerant passage of the compressor and detecting a state of the refrigerant sucked into the compressor; And a second refrigerant state detection sensor provided in the discharge side refrigerant passage of the compressor to detect a state of the refrigerant discharged from the compressor.

In addition, the above-described air conditioner includes: a first valve provided in a refrigerant flow path between an outdoor heat exchanger and an indoor heat exchanger and controlled on / off; A second valve provided on the refrigerant flow path between the outdoor heat exchanger and the four-way valve and controlled on / off; The control unit operates the compressor while the first valve is turned off during the cooling operation, and operates the compressor while the second valve is turned off during the heating operation.

In addition, the above-described air conditioner further includes an expansion device connected in parallel with the second valve; When the second valve is turned off, the refrigerant moving from the outdoor heat exchanger to the four-way valve is made to be decompressed through the expansion device.

According to an aspect of the present invention, a control method of an air conditioner includes a compressor; An outdoor heat exchanger; An indoor heat exchanger; A control method of an air conditioner including a refrigerant path for circulating refrigerant by connecting a compressor, an outdoor heat exchanger, and an indoor heat exchanger in this order, wherein the refrigerant discharged from the compressor by cooling operation is directed toward the outdoor heat exchanger. Keep them all focused; Switching to a heating operation such that all refrigerant concentrated on the outdoor heat exchanger side is moved to the indoor heat exchanger through the compressor; Calculating the amount of refrigerant per unit time passing through the compressor by substituting state information of the refrigerant passing through the compressor into performance data of the compressor; The total amount of refrigerant charged in the air conditioner is determined by integrating the amount of refrigerant per unit time.

In addition, the first valve is provided on the refrigerant flow path between the outdoor heat exchanger and the indoor heat exchanger on / off control; A second valve provided on the refrigerant flow path between the outdoor heat exchanger and the four-way valve and controlled on / off; The method may further include driving the compressor while the first valve is turned off during the cooling operation, and operating the compressor while the second valve is turned off during the heating operation.

Referring to Figures 1 to 4 a preferred embodiment of the present invention made as described above are as follows. 1 is a view showing the configuration of an air conditioner according to an embodiment of the present invention. As shown in FIG. 1, the compressor 118 and the outdoor heat exchanger 122 are the bases of the outdoor unit, and the indoor heat exchanger 116 is the base of the indoor unit.

The indoor heat exchanger 116 is a device that performs heat exchange between the refrigerant and the indoor air. The first expansion device 174 is for adjusting the pressure of the refrigerant flowing into the indoor and outdoor heat exchangers 116 and 122 in the cooling and heating operation mode.

The outdoor heat exchanger 122 is a device that performs heat exchange between the refrigerant and the outdoor air. The compressor 118 is a device that sucks a low pressure refrigerant, converts the refrigerant into a high temperature-high pressure refrigerant, and discharges the refrigerant. The 4-way valve 130 switches the circulation direction of the refrigerant discharged from the compressor 118 according to the cooling mode and the heating mode, so that the refrigerant flows to either the outdoor heat exchanger 122 or the indoor heat exchanger 116. In the cooling mode, the refrigerant discharged from the compressor 118 switches the circulation direction of the refrigerant so that the refrigerant is first supplied to the outdoor heat exchanger 122, and in the heating mode, the refrigerant discharged from the compressor 118 is indoors. The circulation direction of the refrigerant is switched to be supplied to the heat exchanger 116 first. The gas-liquid separator 156 is for separating the liquid refrigerant and the gaseous refrigerant, and the receiver 154 is for storing the liquid refrigerant separated through the gas-liquid separator 156.

The first valve 172 and the first expansion device 174 are sequentially connected to the refrigerant pipe from the receiver 154 to the indoor heat exchanger 116. The first valve 172 is an on / off valve to block the refrigerant flow between the receiver 154 and the indoor heat exchanger 116 as needed. The second valve 176 and the second expansion device 178 are connected in parallel to the refrigerant pipe between the four-way valve 130 and the outdoor heat exchanger 122. The second valve 176 is also an on / off valve, to block the refrigerant flow between the four-way valve 130 and the outdoor heat exchanger 122 as necessary.

However, the first and second valves 172 and 176 are necessary valves when the first and second expansion devices 174 and 178 do not have on / off functions like capillaries. If the first and second expansion devices 174, 178 have on / off functions like the electromagnetic expansion valve, the first and second expansion devices 174, 178 can implement the on / off function through the first and second expansion devices 174, 178. And second valves 172, 176 are not required.

The first refrigerant state detection sensor including the first pressure sensor 182 and the first temperature sensor 184 is connected to the suction side refrigerant pipe of the compressor 118 to provide the state information of the refrigerant sucked into the compressor 118 (eg, Pressure and temperature), and a second refrigerant state detection sensor comprising a second pressure sensor 186 and a second temperature sensor 188 is connected to the discharge-side refrigerant pipe of the compressor 118 so that the compressor 118 is connected. Detects state information (eg, pressure and temperature) of the refrigerant discharged from the.

FIG. 2 is a block diagram showing a control system of the air conditioner shown in FIG. 1. As shown in FIG. 2, a first pressure sensor 182, a first temperature sensor 184, a second pressure sensor 186, and a second temperature are provided at an input side of the controller 202 that controls the overall operation of the air conditioner. The sensor 188 is connected, and the compressor 118, the four-way valve 130, and the first and second valves 172 and 176 are connected to the output side of the controller 202.

The controller 202 is provided with the refrigerant state information detected from each of the sensors 182, 184, 186, and 188 to control the operation of the compressor 118 and the switching of the four-way valve 130 to control the operation of the air conditioner. The on / off operation of the first and second valves 172 and 176 is controlled.

If the first and second expansion devices 174, 178 of FIG. 1 are electronic expansion valves with on / off functions, the control unit 202 may replace the first and second valves 172, 176 with the first and second valves. Control on / off operation of inflation device 174, 178.

3 is a graph showing the relationship of mass to evaporation temperature of a refrigerant. In the air conditioner and control method thereof according to the present invention, the amount of refrigerant passing through the compressor 118 for a unit time is detected, and the amount is accumulated to determine the total amount of refrigerant charged in the refrigerant cycle. At this time, the performance data of the compressor 118 is used to calculate the amount of refrigerant passing through the compressor 118 for a unit time. That is, since the manufacturer of the compressor provides the performance data of the compressor when the compressor is sold, the amount of refrigerant passing through the compressor for the unit time is calculated using the performance data of the compressor.

For example, as shown in FIG. 3, when the condensation temperature Tc of the refrigerant has a predetermined value through the performance data of the compressor, the mass changes according to the change of the evaporation temperature Te of the refrigerant. Know the characteristics. In addition, when the evaporation temperature Te is constant, the mass change of the refrigerant according to the change of the condensation temperature Tc can be known. The amount of refrigerant per unit time can be calculated.

4 is a flowchart illustrating a control method of an air conditioner according to an exemplary embodiment of the present invention, and illustrates a control method for determining a total amount of refrigerant charged in a refrigerant cycle using performance data of a compressor. As shown in FIG. 4, first, the air conditioner is switched to the cooling mode and pump down operation is performed (402). The pump down operation is performed in the cooling mode by turning off the first valve 172 and turning on the second valve 176. Then, the compressor 118 is operated so that the coolant flows in the direction of the arrow in FIG. And to be concentrated on the outdoor heat exchanger 122 side. Through this pump down operation, a liquid refrigerant is present at the outlet side B and the receiver 154 side of the outdoor heat exchanger 122, and the refrigerant is at the inlet side A of the outdoor heat exchanger 122. It will exist.

When the pump-down operation is sufficiently performed to concentrate all the refrigerant toward the outdoor heat exchanger 122, the second valve 176 is turned off and the heating mode is maintained while the first valve 172 is turned off. The compressor 118 is operated (404). At this time, the refrigerant concentrated in the outdoor heat exchanger 122 side bypasses the second valve 178 that is turned off, so that the second expansion device 178, the four-way valve 130, and the gas-liquid separator ( 156 is sucked into the compressor 118, and the refrigerant compressed in the compressor 118 flows back through the four-way valve 130 to the indoor heat exchanger 116. The refrigerant pressure and temperature of the suction side of the compressor 118 and the refrigerant pressure of the discharge side of the compressor 118 while the refrigerant, which has been concentrated on the outdoor heat exchanger 122, flow through the compressor 118 to the indoor heat exchanger 116. And the temperature is detected (406), and the detected value is substituted into the performance data of the compressor 118 to calculate the amount of refrigerant per unit time passing through the compressor 118 (408).

While performing the heating operation for a sufficient time, the amount of refrigerant per unit time passing through the compressor 118 calculated every unit time is accumulated (410). If the condensation pressure Pc of the refrigerant is lower than the preset pressure value Pset (YES in 412), all of the refrigerant concentrated at the outdoor heat exchanger 122 side passes through the compressor 118 to the indoor heat exchanger 116. The final integration result up to this point is determined as the total amount of refrigerant in the refrigerant cycle (414).

The present invention can calculate the current total amount of refrigerant charged in the refrigerant cycle through the rating of the compressor and the temperature and pressure characteristics of the input and output refrigerant of the compressor.

Claims (7)

A compressor; An outdoor heat exchanger; An indoor heat exchanger; A refrigerant passage for connecting the compressor, the outdoor heat exchanger, and the indoor heat exchanger in order to circulate the refrigerant; The cooling operation is performed to concentrate all the refrigerant discharged from the compressor toward the outdoor heat exchanger, and then switch to the heating operation to move all the refrigerant concentrated on the outdoor heat exchanger to the indoor heat exchanger through the compressor. A control unit for calculating the amount of refrigerant per unit time passing through the compressor by substituting the state information of the refrigerant into the performance data of the compressor, and integrating the amount of refrigerant per unit time to determine the total amount of refrigerant charged in the air conditioner. Harmonizer. The method of claim 1, The air conditioner further comprises a four-way valve to switch the circulation direction of the refrigerant discharged from the compressor according to the cooling mode and the heating mode to flow the refrigerant to either the outdoor heat exchanger or the indoor heat exchanger. The method of claim 2, A first refrigerant state detection sensor installed in the suction side refrigerant passage of the compressor to detect a state of the refrigerant sucked into the compressor; And a second refrigerant state detection sensor installed in the discharge side refrigerant passage of the compressor to detect a state of the refrigerant discharged from the compressor. The method of claim 3, wherein A first valve provided in a refrigerant passage between the outdoor heat exchanger and the indoor heat exchanger and controlled on / off; A second valve provided on a coolant path between the outdoor heat exchanger and the four-way valve and controlled on / off; The control unit is configured to operate the compressor while the first valve is turned off during the cooling operation, and to operate the compressor while the second valve is turned off during the heating operation. 5. The method of claim 4, An expansion device in parallel with the second valve; And the refrigerant moves from the outdoor heat exchanger to the four-way valve when the second valve is turned off to reduce the pressure through the expansion device. A compressor; An outdoor heat exchanger; An indoor heat exchanger; In the control method of the air conditioner comprising a refrigerant flow path for connecting the compressor, the outdoor heat exchanger, the indoor heat exchanger in order to circulate the refrigerant, Perform a cooling operation to concentrate all the refrigerant discharged from the compressor toward the outdoor heat exchanger; Switching to a heating operation such that all refrigerant concentrated on the outdoor heat exchanger side is moved to the indoor heat exchanger through the compressor; Calculating the amount of refrigerant per unit time passing through the compressor by substituting state information of the refrigerant passing through the compressor into performance data of the compressor; And controlling the total amount of refrigerant charged in the air conditioner by integrating the amount of refrigerant per unit time. The method of claim 6, A first valve provided in a refrigerant passage between the outdoor heat exchanger and the indoor heat exchanger and controlled on / off; A second valve provided on a coolant path between the outdoor heat exchanger and a four-way valve to be controlled on / off; And operating the compressor while the first valve is turned off during the cooling operation, and operating the compressor while the second valve is turned off during the heating operation.

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